Mix the sugar, salt, grated lemon zest and softened butter until creamy. Stir in eggs. Knead in the flour, baking powder and desiccated coconut. Form a roll about 5 cm in diameter. Wrap in foil and put in a cool place for a few hours (or overnight). Cut the roll into thin slices and place them on a baking sheet lined with baking paper. Brush with water and sprinkle with desiccated coconut. Bake in the preheated oven at 160-180 degrees for 8-10 minutes.